Concealment method and apparatus and naval vessel provided with at least such an apparatus

ABSTRACT

A concealment that covers all or a main part of naval vessels and their surroundings and crew, by making provision for coupling a flow of air with an injection of fluid to cause formation of a cloud and to orient the cloud to optimize coverage of the vessel and the surroundings to be protected. A concealment apparatus includes a gas turbine coupled to a conduit discharging a flow of smoke composed of a combustion gas loaded with droplets of fluid in suspension. The conduit includes two branches that emerge on each lateral half-hull of the hull of the vessel. The branches are symmetrical with respect to a vertical symmetry plane of the ship and, through their curvature, have roughly a direction oriented towards the rear of the ship. In this way, the flow of smoke is also oriented towards the rear of the ship.

TECHNICAL FIELD

The invention relates to a method and to an apparatus for concealing a naval vessel such as a ship, a pleasure boat or a watercraft, as well as to a naval vessel equipped with at least one such apparatus.

The context of the invention is the protection of a naval vessel, at rest or in movement, and its surroundings by a cloud for concealing the vessel at least in the visible radiation range. This concealment aims to prevent any act of aggression or boarding of this vessel.

The field concerns the production of an opaque environment formed in general from particles, for example liquid particles, in suspension in the air in order to form a cloud, or, for example, solid particles also in suspension in the air in order to generate smoke.

In the case where the vessel to be protected is moving on the water, the production of an opaque environment must be able to coincide with the movement of the vessel. The installation of means for producing such an environment on or in the vessel is therefore to be provided. In addition, since the concealment is intended to cover all or at the very least the main part of the vessel, it is necessary to ensure that the environment allows such coverage in space and over time.

PRIOR ART

The use of smoke-generating cartridges is known for creating smoke screens. However, these screens remain of small size and are effective only for a short period and provide only a small output. In addition, the efficacy of concealment is not sufficient since the opaque coverage is not uniform.

In general, pyrotechnics provide smoke that cannot conceal a vessel satisfactorily (dimensions, duration, efficacy) and which gives rise to high cost as well as a degree of not insignificant level of risk in handling.

DISCLOSURE OF THE INVENTION

The invention aims to dispense with these drawbacks by proposing the production of an effective, long-lasting concealment which covers all or the main part of vessels and their surroundings and crew. The aim is also to disorientate and disturb any aggressors in order to dissuade them from any attempt at boarding. To do this, the invention makes provision for coupling an airflow with an injection of fluid able to cause the formation of a cloud and to orient this cloud in order to optimise coverage of the vessel to be protected over time and in space.

More precisely, the present invention relates to a method for concealing a naval vessel, preferably in movement, comprising at least one deck and a hull. The method consists in integrating in the vessel at least one smoke generator, this integration being able to be achieved on the deck and/or in the vessel, in particular substantially at or above the waterline, injecting a fluid at the output of the smoke generator and guiding the gas flow thus loaded with fluid in suspension, referred to as the flow of smoke, to at least one outlet formed in the hull of the vessel, so as to direct said flow, for example, towards the rear or towards to the front of the vessel, preferably from a position substantially at or above the waterline of the vessel. The smoke generator or generators can be integrated at any point on the vessel such as for example at the bow, amidships or at the stern of the vessel.

According to preferred embodiments:

an injection of coloured, powdery, odorous and/or smoke-generating additives is also effected at the gas outlet or downstream of the gas outlet;

an injection of graphite powder is also effected at the outlet of the smoke generator so as to cause concealment in the infrared radiation range;

the guidance of the flow is broadened at the outlet of the smoke generator in order to substantially reduce the speed of the smoke;

the guidance of the flow of smoke is configured so that the guidance outlet out of the hull is implemented between the middle and the front of the naval vessel and at or above the flotation line;

the guidance is of adaptable orientation, at the outlet from the hull of the naval vessel, by orientation in a reference plane parallel to the deck or decks of the vessel and/or in a plane perpendicular to the reference plane, in order to orient the flow of smoke discharged at the waterline according to the movement of the vessel and the sailing conditions so that the flow of smoke discharged is directed between the deck or decks and the waterline;

the guidance is of variable length so that the guidance is suited to the dimensions of the hull of the vessel;

the flow of smoke is cooled and made denser by humidification before leaving the hull of the vessel in order to cause vaporisation at the discharge and to keep the smoke placed over the stretch of water that surrounds the vessel;

the flow of smoke is regulated so that its discharge speed is almost zero.

The invention also relates to an apparatus for concealing a naval vessel, intended to implement the method. This apparatus comprises a gas turbine composed of a gas generator and a gas exhaust pipe connected to a reservoir of fuel. The exhaust pipe is equipped with at least one fluid injector connected to at least one reservoir, for injecting this fluid, in particular oil, into the exhaust gases of the gas turbine and to form a flow of gas with fluid in suspension (F3), referred to as a flow of smoke, and is coupled to at least one conduit for guiding the flow of smoke.

According to advantageous embodiments:

the or each conduit comprises at least one frustoconical divergent portion, connected to the pipe in order to substantially reduce the speed of the flow of smoke;

the or each conduit or branch is equipped with an orientable grille in a region of a conduit end, the grille being able to direct and/or mix the flow of smoke that passes through the conduit or branch;

an external flow injector in the flow of gas is arranged in an end region of the or each conduit or branch in order to cool and make denser the flow of smoke, the external fluid being in particular sea water, at a temperature substantially less than that of the flow of gas in said region;

the or each conduit or branch is equipped at the end with a nozzle that can be oriented in at least one plane, for example in any direction, in order to direct the flow of smoke at the outlet of the conduit or branch, so that the concealment is as effective as possible according to the conditions (meteorological, movement, attack, etc.) imposed on the vessel;

the or each conduit comprises a portion fitted in the conduit or branch, with telescopic adjustment means in order to vary and adapt the length of the or each conduit or branch;

the or each conduit is sized and configured so as to adjust the pressure drops in the flow below a given ceiling, in order to avoid overpressure at the turbine;

the or each conduit can comprise means for regularising the flow of gas (frustoconical divergent exit cones, valves, shutters, etc.) in order to reduce the speed of the flow of gas and to make it tend towards an almost zero value at the discharge from the conduit;

an opening flap is arranged at the end of the conduit and controlled so that said flap opens at the start-up of the gas turbine, this flap preventing sea water from entering the conduit as far as the gas turbine and preventing problems of corrosion, watertightness, etc.;

the gas generator, the pipe and the reservoirs are integrated in a protective chamber, the reservoirs preferably being separated from the gas generator and the pipe by at least one protective partition;

the apparatus comprises at least one additive injector arranged so as to effect an injection of coloured, powdery, odorous and/or smoke-generating additives at the gas outlet or downstream of the gas outlet.

The invention also relates to a naval vessel equipped with at least one deck, a hull and at least one such apparatus. The apparatus or apparatuses can be arranged on a deck or in a hold, at any place in the vessel. The lengths of the conduits and branches are then determined so as to emerge out of the hull of the vessel through preformed openings.

Advantageously, the apparatus is arranged at the front of the vessel centrally, and comprises a conduit with two branches having a common end for coupling to the pipe of the gas turbine and ends emerging on each of the half hulls. The conduit may be arranged downstream or upstream of the gas turbine, preferably with branches roughly oriented towards the rear of the vessel in both cases.

When the vessel comprises at least two apparatuses, each apparatus may be arranged laterally close to a half hull and comprise only one conduit with an end that emerges out of the half hull.

The or each apparatus may be integrated in a chamber when this apparatus is installed on the deck of the vessel, in order to protect the apparatus from waves and spray and to facilitate traffic on the deck.

In addition, the conduit or conduits of the apparatuses are arranged so that the flow of smoke emerges at the front of the vessel, for example as close as possible to the waterline. Preferably the conduit or conduits of the apparatuses comprise at least one horizontal portion and/or one vertical portion.

The means for orienting the end nozzle of the or each conduit may make it possible to adjust the outlet angle of the flow of smoke, for example according to the movement of the vessel and the sailing conditions so that the smoke discharged is directed for example between the deck or decks and the waterline, in a given direction.

PRESENTATION OF THE FIGURES

Other information, features and advantages of the present invention will emerge from reading the following non-limiting description with reference to the accompanying schematic drawings, in which:

FIG. 1 is a diagram of an auxiliary engine such as for example a gas turbine of a concealment apparatus according to the invention;

FIG. 2 is a partial side view of a ship equipped with a concealing apparatus in a chamber installed on the deck of this vessel;

FIG. 3 is a side view of a short ship equipped with a concealing apparatus in a forward hold of the ship;

FIGS. 4 a and 4 b are partial top views of the ship according to FIG. 3 with a double conduit of the concealment apparatus installed in a forward hold of the vessel, upstream and downstream of the gas turbine, respectively;

FIG. 5 is an enlarged partial view of the apparatus according to FIG. 4 detailing the structure elements at the end of a branch of the double conduit; and

FIGS. 6 a and 6 b are a side view and a top view of a long tanker equipped with four concealment apparatuses according to the invention.

DETAILED DESCRIPTION

Throughout the text, the qualifiers “upstream” and “downstream” relate to relative locations of elements of the naval vessels in the direction of standard sailing of these vessels. The front of such a vessel is upstream and corresponds to the bow, whereas the rear is downstream and corresponds to the stern of the vessel. In addition, “horizontal” means parallel to the deck or decks of the vessel and “vertical” means perpendicular to this deck or these decks.

With reference to the schematic diagram in FIG. 1, an engine of the gas turbine type, such as for example an engine of the GPU (ground power unit) type, is modified in order to serve as a “smoke turbine” in the concealment apparatus 10 according to the invention. A GPU is a fixed or movable gas turbine for starting the main engines and generating non-propulsive power (pneumatic, electrical or hydraulic power) of a vehicle or aircraft.

The GPU 1 is composed mainly of a gas generator 2 and a gas exhaust pipe 3 connected to a fuel reservoir 41 and at least one reservoir 42 for fluid, oil H1 in the example, which is able to remain in the exhaust gases in the form of suspended droplets. The gas generator 2 comprises: an air compressor 21—the air (arrows F1) entering, axially or radially, through a sleeve 5; a combustion chamber 22 for a mixture of air and fuel, the fuel coming from the reservoir 41 being introduced into the chamber 22 through fuel injectors 23; as well as a turbine 24 for expansion of the burnt gases and driving of the compressor 21 via a shaft 25. The burnt gases (arrows F2) are ejected through the pipe 3. These components are generally enclosed in a casing 6 open at the inlet 5 a of the sleeve 5 and at the outlet 3 s of the pipe 3, which is at the same time the outlet for the GPU 1.

In order to form a smoke turbine, the GPU 1 is modified by adding, at the outlet of the exhaust pipe 3, an annular ring 7 coupled to the casing 6 and equipped with fluid injectors 71, for example, for oil, coming from the reservoir 42. This injection of fluid is propelled by a pump 72 and atomised by the injector 71 in the hot fast-moving exhaust gases emerging through the pipe 3.

Such an atomisation forms a gas flow loaded with droplets of fluid in suspension (arrows F3), referred to as “loaded gas flow” or “flow of smoke”. The annular ring 7 is coupled to a conduit 11 for discharging smoke gas to the outside in order to conceal the ship. The conduit 11 is made from stainless steel in the example. The length of this conduit 11 and its configuration are then adapted so as to emerge in the hull of the naval vessel for which the apparatus 10 is intended. This adaptation is in particular dependent on the dimensions of the vessel and the planned location—on the deck or in a hold—for this apparatus. FIGS. 2 and 3, which follow, illustrate the installation, on the deck and in the bottom of a hold of a ship, of such apparatuses, which comprise conduits, smoke turbines 1 and reservoirs 41, 42.

Advantageously, apart from oil, coloured, powdery, odorous and/or smoke-generating additives may also be injected through the injectors 71 or any other injection manifold, in order to create or reinforce the surprise and dissuasive effect of the flow of smoke. It is also advantageous to inject graphite powder, which affords concealment in the infrared radiation range. Alternatively, it is necessary to refrain from injecting graphite powder if the aim is to be able to direct the ship using infrared binoculars through the flow of smoke after it has formed around the ship.

FIG. 2 is a partial side view of a ship 100 equipped with a concealment apparatus 10 according to the invention comprising a smoke turbine 1, for example the GPU described with reference to FIG. 1, the reservoirs 41 and 42, and the conduit 11. The smoke turbine 1 and the reservoirs 41 and 42 are arranged in a protective chamber 8 installed on the deck 10P of this ship 100.

The conduit 11 comprises a frustoconical divergent portion 12—referred to as a “divergent exit cone”—connected to the pipe 3 at the discharge from the smoke turbine 1. This divergent exit cone 12 substantially reduces the speed of the gas flow F3 so that, at the end of the outlet 14 of the conduit 11 through an orifice 13 formed in the hull 101 of the vessel 100, this speed is almost zero. The conduit 11 has elbows C1 to C3, a horizontal portion P1 and a vertical portion P2.

The horizontal portion P1 makes it possible to move the outlet 14 of the conduit 11 towards the front AV of the ship 100, and the vertical portion P2 emerges at the outlet 14 close to the waterline LF of the ship 100. It is in fact sought to have an outlet 14 upstream—in order to enable the smoke to cover the whole of the ship 100 because of the relative speed of the ship—and close to the waterline LF since the smoke remains “attached” to the stretch of water and then rises over time. The outlet 14 remains above this waterline LF in order to prevent the entrance of waves or spray.

The conduit 11 is sized and configured so that the number of elbows, here three elbows C1 to C3, is reduced to a minimum in order the minimise the pressure drops in the flow of smoke F3 below a ceiling, determined in advance for the purpose of avoiding overpressures at the smoke turbine 1.

Advantageously, a flap 16 for opening/closing the outlet 14 of the conduit 11 on the hull 103 is arranged at the end of the conduit. This flap 16 is controlled from the control centre (not shown) of the ship 100 so that said outlet 14 opens when the smoke turbine 1 starts up. It would in fact be detrimental to allow waves and spray to enter the conduit 11 via this open outlet 14 when the concealment apparatus is not operating. Problems of corrosion, watertightness or the like, caused by the presence of sea water, are thus avoided.

FIGS. 3 and 4 a illustrate, in side and (partial) top views of a short ship 102, another example of installation in a forward hold 31 of the smoke turbine 1 already described. A ship is said to be “short” when, for example, it does not exceed 50 m in length.

The concealment apparatus 10′ comprises, in this case, the smoke turbine 1 already described, and a conduit 11′ with two branches 11′a and 11′b having a common portion connected at the outlet of the smoke turbine 1. In this example, the conduit 11′ is installed downstream of the smoke turbine 1. The fact that the ship 102 is short makes it possible to limit the number of apparatuses to only one, arranged at the front AV of the ship 102 so that the flow of smoke F3 leaves the conduit 11′ also from the front of the ship 102.

As illustrated by the top view in FIG. 4 a, the two conduit branches 11′a and 11′b emerge on each lateral half-hull 103 a and 103 b of the hull 103. The branches 11′a and 11′b are symmetrical with respect to a vertical symmetry plane Pv of the ship 102 and, through their curvature, have roughly a direction oriented (arrow F4) towards the rear AR of the ship 102. In this way, the flow of smoke F3 is also oriented mainly towards the rear AR of the ship 102.

In a variant of FIG. 4 a, the partial side view of FIG. 4 b shows a conduit 11″ of the same type as in FIG. 4 a but connected upstream of the smoke turbine 1. In this case, the symmetrical branches 11″a and 11″b are also oriented towards the rear AR of the vessel 102 so that the flow of smoke F3 is set up along the vessel, from upstream to downstream.

FIG. 5 details the structure elements in the end region 15 of the branch 11′a of the conduit 11′ improving the directivity and quality of concealment of the flow of smoke at the outlet of the branches 11′a and 11′b. The partial view in FIG. 5 is an enlarged view of the apparatus according to FIG. 4 a. As in FIG. 1, the GPU 1 is connected to a ring 7 which is equipped with fluid injectors 71 and itself connected to the conduit 11′.

The end region 15 of each branch 11 a and 11 b (only the end of the branch 11 a is visible in FIG. 5) is equipped with an orientable grille 17 g with shutters 17 c. The shutters 17 c of the grille 17 g have a set of rotation spindles 17 a controlled remotely at the control centre (not shown). The grille 17 g is more precisely installed in this example at the outlet end 14 of the branch 11′a. The flow of smoke F3 is thus finely oriented in the horizontal plane of FIG. 5.

In addition, water injectors 18 are arranged in said region 15, upstream of the grille 17 g. Water, sea water in the example, at low temperature (10 to 20° C.) substantially below the temperature of the flow of smoke (above 40° C.) is thus injected via these injectors 18. This injection cools the flow of smoke F3 and makes it denser in order to make it heavier and “attach” it to the stretch of water that surrounds the ship 102. The flow of smoke F3 then detaches from the stretch of water and conceals the whole of the ship 102.

In addition, each branch 11′a is advantageously equipped, at the outlet end 14, with a nozzle 19 that can be oriented in the horizontal plane of the figure and in a vertical plane perpendicular to the horizontal plane. To do this, twin-axis articulation means 19 a are integrated in the nozzle 19, close to the end 19 e thereof. The flow of smoke is thus oriented in order to be able to attach to the stretch of water that surrounds the ship 102. In addition, the nozzle 19 fits telescopically in the branch of the conduit 11 a. The fitting is adjusted by rack-type adjustment means 19 c, also controlled from the control centre. It is thus possible to vary and adapt the length of the branch 11′a (and, in a similar manner, the branch 11 b).

FIGS. 6 a and 6 b are schematic side and top views of a long tanker 104 (for example with a length greater than 300 m) equipped with four concealment apparatuses installed at the bottom of a forward hold 32 and a hold at the middle 33 of the tanker 104. Two apparatuses 10″a are installed close to the lateral half-hull 105 a of the hull 105 of the ship 104 and two apparatuses 10″b are installed close to the half-hull 105 b of the hull 105. Close to each lateral half-hull 105 a and 105 b, the apparatuses 10″a and 10″b are arranged substantially at the middle MI and towards the front AV of the ship 105.

The apparatuses 10″a and 10″b are composed of smoke turbines 1, such as those described previously, connected to conduits 11″a and 11″b, corresponding respectively to the branch 11′a and to the branch 11′b described above with reference to FIG. 4 a or FIG. 5. The lengths of the conduits 11″a and 11″b are determined so that they can emerge out of the hull 105 of the ship through preformed orifices 13.

The invention is not limited to the embodiments described and depicted. Thus it is possible to add means for regularising the flow of smoke: valves, shutters, etc. The fluid added to the exhaust gas to serve as a load in suspension and to form the smoke may be any liquid of organic or aqueous nature, suited to the production of such a suspensive effect.

In addition, in the case of a ship of average length, for example greater than or approximately equal to 100 m, it is possible to limit the number of concealment apparatuses to two installed towards the upstream end of the vessel.

Moreover, means other than gas turbine compressors may be used as a smoke generator, for example fans of suitable size and output.

Furthermore, it is advantageous to use the existing pipework of naval vessels to serve as smoke-discharge conduits according to the invention, at least partly. 

1-10. (canceled)
 11. A method for concealing a naval vessel including at least one deck and a hull, the method comprising: integrating in the vessel at least one gas turbine, the integrating being able to be made on a deck of the vessel and/or in the vessel, substantially at or above a waterline; injecting a fluid at a discharge from the gas turbine; and guiding a flow of gas thus loaded with fluid in suspension, as a flow of smoke, to at least one outlet formed in the hull of the vessel, to direct the flow of smoke.
 12. A concealing method according to claim 11, wherein an injection of additives chosen from coloured, powdery, odorous, smoke-generating additives and/or graphite powder is also effected at the outlet of the smoke generator.
 13. A concealing method according to claim 11, wherein the guiding the flow of smoke is configured so that the outlet out of the hull is produced at or above the waterline of the naval vessel.
 14. A concealing method according to claim 11, wherein the guiding is of adaptable orientation, at the outlet from the hull of the naval vessel, by orientation in a reference plane parallel to the at least one deck of the vessel and/or in a plane perpendicular to the reference plane, to orient the flow of smoke at the waterline according to movement of the vessel and sailing conditions, so that the flow of smoke and the outlet is directed between the at least one deck and the waterline.
 15. A concealing method according to claim 11, wherein the flow of smoke is cooled and made denser by humidification before emerging from the hull of the vessel to cause a vaporization at the outlet and to keep the smoke placed over a stretch of water that surrounds the vessel.
 16. An apparatus for concealing a naval vessel configured to implement the method according to claim 11, and comprising a gas turbine including a gas generator and a pipe for ejecting the gases, which is connected to a fuel reservoir, wherein the exhaust pipe includes at least one fluid injector connected to at least one reservoir, to inject the fluid, or an oil, into the exhaust gases from the gas turbine and to form a flow of gas with a fluid in suspension, as the flow of smoke, and is coupled to at least one conduit or guide conduit branch for the flow of smoke.
 17. An apparatus according to claim 16, wherein each conduit or branch comprises at least one frustoconical divergent portion, connected to the pipe to substantially reduce a speed of the flow of smoke.
 18. An apparatus according to claim 16, wherein an injector injecting external fluid into the flow of gas is arranged in an end region of each conduit or branch to cool the flow of smoke and make it denser, or the external fluid is sea water at a temperature substantially below that of the flow of gas at the region.
 19. An apparatus according to claim 16, wherein each conduit or branch includes at an end with a nozzle orientable in at least one plane to direct the flow of smoke at the outlet of the conduit or branch or with a grille orientable in an end region of the pipe, the grille configured to direct the flow of smoke that passes through the conduit or branch.
 20. A naval vessel comprising at least one deck, a hull, and at least one apparatus according to claim 16, the apparatus arranged on a deck or in a hold of the vessel, lengths of the conduits and branches determined to emerge out of the hull of the vessel through preformed openings. 